:root{
  /* Brand palette (teal-forward, matching book aesthetic) */
  --brand:#0f766e;           /* primary teal */
  --brand-2:#14b8a6;         /* accent teal */
  --brand-3:#0ea5a6;         /* lighter accent */
  --ink:#0f172a;             /* heading/body */
  --muted:#64748b;           /* secondary text */
  --line:#e2e8f0;            /* borders */
  --bg:#ffffff;              /* page */
  --panel:#f8fafc;           /* sections */
  --card:#ffffff;            /* cards */
  --shadow:0 10px 30px rgba(2,6,23,.08);
  /* Links */
  --link:#2563eb;            /* blue-600 */
  --link-hover:#1d4ed8;      /* blue-700 */
  /* Layout */
  --radius:14px;
  --radius-sm:10px;
  --space:18px;
  --space-lg:64px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Noto Sans,sans-serif;background:var(--bg);color:var(--ink)}
html{scroll-behavior:smooth}
:root{scroll-padding-top:72px}
img{max-width:100%;display:block}
.container{max-width:1100px;margin:0 auto;padding:0 20px}
.center{text-align:center}
.tiny{font-size:12px;color:var(--muted)}

/* Typography scale */
h1,h2,h3,h4{font-weight:800;letter-spacing:-.015em;margin:0 0 .3em 0}
h1{font-size:clamp(28px,4vw,42px)}
h2{font-size:clamp(24px,3.2vw,36px)}
h3{font-size:clamp(20px,2.4vw,26px)}
h4{font-size:18px}
p{line-height:1.7;margin:.6em 0}
ul,ol{line-height:1.6}

.site-header{position:sticky;top:0;backdrop-filter:saturate(1.2) blur(10px);background:rgba(255,255,255,.85);border-bottom:1px solid var(--line);z-index:10}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 0}
.brand{display:flex;align-items:center;gap:12px}
.brand-cover{width:40px;height:40px;border-radius:6px;box-shadow:0 2px 6px rgba(0,0,0,.15)}
.brand-text h1{font-size:18px;margin:0}
.brand-text .subtitle{margin:0;color:var(--muted);font-weight:500}
.nav{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.nav a{color:var(--ink);text-decoration:none;margin-left:0;font-weight:600}
.nav .btn{margin-left:0}
/* Ensure header CTA text stays white on the green background */
.nav .btn-primary{color:#fff}
.nav .btn-primary:hover,
.nav .btn-primary:focus,
.nav .btn-primary:active,
.nav .btn-primary:visited{
  color: #fff !important;
  text-shadow: 0 1px 2px rgba(0,0,0,0.12);
}

.btn{display:inline-block;padding:10px 14px;border-radius:var(--radius-sm);border:1px solid var(--line);text-decoration:none;color:var(--ink);font-weight:700;transition:.2s ease box-shadow,.2s ease transform,.2s ease background}
.btn:hover{}
.btn-primary{background:linear-gradient(135deg,var(--brand),var(--brand-2));border-color:transparent;color:#fff}
.btn-primary:hover{
}
}
.btn:hover {
  color: var(--ink);
}
.btn-ghost{background:transparent}
.btn:focus-visible{outline:3px solid rgba(37,99,235,.35);outline-offset:2px}
.nav a:focus-visible{outline:2px solid rgba(37,99,235,.35);outline-offset:3px;border-radius:8px}

.hero{padding:72px 0;background:radial-gradient(1200px 400px at 0% -10%, rgba(20,184,166,.12), transparent 60%), radial-gradient(1200px 400px at 100% 0%, rgba(14,165,166,.12), transparent 60%)}
.grid-2{display:grid;grid-template-columns:1.2fr .8fr;gap:32px;align-items:center}
.hero-copy h2{margin:.2em 0}
.cta-group{display:flex;gap:10px;flex-wrap:wrap;margin-top:12px}
.hero-art{justify-self:center}

.section{padding:var(--space-lg) 0}
.section.alt{background:var(--panel)}
.narrow{max-width:760px}
.pill-list{display:flex;flex-wrap:wrap;gap:8px;padding:0;margin:12px 0}
.pill-list li{list-style:none;border:1px solid var(--line);border-radius:999px;padding:8px 12px;background:#fff}

.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.card h4{margin-top:0}

/* Table of contents styles */
.toc{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.toc .toc-group{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.toc h4{margin:0 0 8px 0}
.toc ul{margin:0;padding-left:18px}
.toc li{margin:6px 0;line-height:1.5;color:var(--muted)}
.toc a{color:var(--link);text-decoration:none}
.toc a:hover{color:var(--link-hover);text-decoration:underline}
/* Show a subtle "Sample" badge after linked items */
.toc a::after{
  content:"Sample";
  margin-left:8px;
  padding:2px 6px;
  border-radius:999px;
  border:1px solid rgba(37,99,235,.28);
  background:rgba(37,99,235,.08);
  color:var(--link-hover);
  font-size:11px;
  font-weight:600;
  line-height:1;
  vertical-align:middle;
}

.site-footer{border-top:1px solid var(--line);background:#fff}
.footer-inner{display:flex;justify-content:space-between;align-items:center;padding:18px 0}
.footer-nav a{margin-left:12px;color:var(--ink);text-decoration:none}
/* Keep footer primary button readable on green background */
.site-footer .btn-primary{color:#fff}
.site-footer .btn-primary:hover,
.site-footer .btn-primary:focus,
.site-footer .btn-primary:active,
.site-footer .btn-primary:visited{
  color: #fff !important;
  text-shadow: 0 1px 2px rgba(0,0,0,0.12);
}

/* Responsive breakpoints */
@media (max-width:1200px){
  .toc{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:900px){
  .grid-2{grid-template-columns:1fr}
  .grid-3{grid-template-columns:1fr}
  .toc{grid-template-columns:1fr}
  .header-inner{flex-wrap:wrap}
  .brand-text h1{font-size:16px}
  .brand-cover{width:36px;height:36px}
}
@media (max-width:700px){
  .section{padding:44px 0}
  .container{padding:0 16px}
  .pill-list{gap:6px}
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion:reduce){
  *{animation-duration:0.001ms !important;animation-iteration-count:1 !important;transition-duration:0.001ms !important;scroll-behavior:auto !important}
}